Electromagnetic simulation of low-pass birdcage coil

Abstract

Magnetic resonance imaging (MRI) is a widely used non-invasive imaging modality that provides a variety of high-resolution soft-tissue contrast and functional information. The development of imaging technique employing the phenomenon of nuclear magnetic resonance is focused on obtaining the best possible tissue contrast, maximisation of ratio defined by signal-to-noise-ratio (SNR) and improving the image quality. SNR can be improved by the use of contrast agents and higher-field scanners, however these are better RF coils that often provide more significant gains. Using full-wave analysis and design tools becomes especially important when the coil dimensions approach a significant fraction of a wavelength. In this paper, modelling of RF coil is presented by using special-purpose software for electromagnetic simulations. The methodology of the research assumes making numerical calculations of RF coil. The presented approach of a design of radiofrequency (RF) coils for MRI scanners using lumped circuit modelling based techniques begins to fail at high frequencies, and therefore more accurate models based on the electromagnetic field calculations must be used. This paper presents simple simulations of the electric and magnetic field in LP birdcage coil.